diff --git a/README.rst b/README.rst
index 859f80e..ca4df21 100644
--- a/README.rst
+++ b/README.rst
@@ -470,6 +470,30 @@ Here are the 5 steps to setup a Deployment dashboard in Buildbot Travis.
            ${stage} is the retrieved from the Deployment dashboard.
            ${version} is retrieved from the Deployment dashboard.
 
+Configuring Travis Defaults
+===========================
+
+The YAML file or Python dict passed to ``TravisConfigurator`` supports a few keys to set some environment defaults.
+
+Default Matrix
+--------------
+The ``default_matrix`` key contains the default values for any keys the repository's ``.travis.yml`` does not specify.
+
+Example::
+
+    default_matrix:
+      os: linux
+      dist: debian_7
+      language:
+        python: 2.7
+        c:
+          compiler: gcc
+        c++:
+          compiler: g++
+
+This example sets the default ``os`` to ``linux``, the default ``dist`` to ``debian_7``, and sets default values for three languages.
+If the ``.travis.yml`` has ``language: c``, then it will have ``compiler`` set to ``gcc``.
+
 How it works
 ============
 
diff --git a/buildbot_travis/configurator.py b/buildbot_travis/configurator.py
index 6f5911d..a8f2c8a 100644
--- a/buildbot_travis/configurator.py
+++ b/buildbot_travis/configurator.py
@@ -356,7 +356,7 @@ def uniq(tags):
         # Define the builder for the main job
         f = factory.BuildFactory()
         vcsManager.addSourceSteps(f)
-        f.addStep(TravisSetupSteps())
+        f.addStep(TravisSetupSteps(cfgdict=self.cfgdict))
 
         self.config['builders'].append(BuilderConfig(
             name=job_name,
@@ -379,6 +379,7 @@ def uniq(tags):
         vcsManager.addSourceSteps(f)
         f.addStep(TravisTrigger(
             scheduler=job_name,
+            cfgdict=self.cfgdict,
         ))
         properties = dict(TRAVIS_PULL_REQUEST=False)
         properties.update(self.properties)
@@ -431,6 +432,7 @@ def uniq(tags):
             vcsManager.addSourceSteps(f)
             f.addStep(TravisTrigger(
                 scheduler=job_name,
+                cfgdict=self.cfgdict,
             ))
 
             self.config['builders'].append(BuilderConfig(
diff --git a/buildbot_travis/steps/base.py b/buildbot_travis/steps/base.py
index 5f9a136..76cb8f9 100644
--- a/buildbot_travis/steps/base.py
+++ b/buildbot_travis/steps/base.py
@@ -70,7 +70,7 @@ def getStepConfig(self):
 
         self.addCompleteLog(filename, travis_yml)
 
-        config = TravisYml()
+        config = TravisYml(self.cfgdict)
         try:
             config.parse(travis_yml)
         except TravisYmlInvalid as e:
diff --git a/buildbot_travis/steps/create_steps.py b/buildbot_travis/steps/create_steps.py
index a80d065..e0e20a0 100644
--- a/buildbot_travis/steps/create_steps.py
+++ b/buildbot_travis/steps/create_steps.py
@@ -217,6 +217,10 @@ class TravisSetupSteps(ConfigurableStep):
     MAX_NAME_LENGTH = 47
     disable = False
 
+    def __init__(self, cfgdict, **kwargs):
+        self.cfgdict = cfgdict
+        ConfigurableStep.__init__(self, **kwargs)
+
     def addSetupVirtualEnv(self, python):
         step = SetupVirtualEnv(python, doStepIf=not self.disable)
         self.build.addStepsAfterLastStep([step])
diff --git a/buildbot_travis/steps/spawner.py b/buildbot_travis/steps/spawner.py
index 99db15a..ba3d524 100644
--- a/buildbot_travis/steps/spawner.py
+++ b/buildbot_travis/steps/spawner.py
@@ -23,10 +23,12 @@
 
 
 class TravisTrigger(Trigger, ConfigurableStepMixin):
-    def __init__(self, scheduler, **kwargs):
+
+    def __init__(self, scheduler, cfgdict, **kwargs):
         if "name" not in kwargs:
             kwargs['name'] = 'trigger'
         self.config = None
+        self.cfgdict = cfgdict
         Trigger.__init__(
             self,
             waitForFinish=True,
diff --git a/buildbot_travis/tests/test_travisyml.py b/buildbot_travis/tests/test_travisyml.py
index a121db1..a7573bf 100644
--- a/buildbot_travis/tests/test_travisyml.py
+++ b/buildbot_travis/tests/test_travisyml.py
@@ -27,7 +27,9 @@ class TravisYmlTestCase(unittest.TestCase):
 
     def setUp(self):
         self.t = TravisYml()
-        self.t.config = {}
+        self.t.config = {'language': 'python'}
+        self.t.load_cfgdict_options()
+        self.t.parse_language()
 
 
 class TestYamlParsing(TravisYmlTestCase):
@@ -102,7 +104,8 @@ def test_singleenv(self):
 
         self.t.parse_matrix()
         self.assertEqual(
-            self.t.matrix, [dict(python="python2.6", env=dict(FOO='1', BAR='2')), ])
+            self.t.matrix, [dict(python="2.7", env=dict(FOO='1', BAR='2'),
+                                 os='linux', dist='precise', language='python'), ])
 
     def test_multienv(self):
         self.t.config["env"] = ["FOO=1 BAR=2", "FOO=2 BAR=1"]
@@ -112,8 +115,10 @@ def test_multienv(self):
 
         self.t.parse_matrix()
         self.assertEqual(self.t.matrix, [
-            dict(python="python2.6", env=dict(FOO='1', BAR='2')),
-            dict(python="python2.6", env=dict(FOO='2', BAR='1')),
+            dict(python="2.7", env=dict(FOO='1', BAR='2'), os='linux',
+                 dist='precise', language='python'),
+            dict(python="2.7", env=dict(FOO='2', BAR='1'), os='linux',
+                 dist='precise', language='python'),
         ])
 
     def test_globalenv(self):
@@ -124,8 +129,10 @@ def test_globalenv(self):
 
         self.t.parse_matrix()
         self.assertEqual(self.t.matrix, [
-            dict(python="python2.6", env=dict(FOOBAR='0', FOO='1', BAR='2')),
-            dict(python="python2.6", env=dict(FOOBAR='0', FOO='2', BAR='1')),
+            dict(python="2.7", env=dict(FOOBAR='0', FOO='1', BAR='2'),
+                 os='linux', dist='precise', language='python'),
+            dict(python="2.7", env=dict(FOOBAR='0', FOO='2', BAR='1'),
+                 os='linux', dist='precise', language='python'),
         ])
 
     def test_emptymatrixlenv(self):
@@ -136,7 +143,132 @@ def test_emptymatrixlenv(self):
 
         self.t.parse_matrix()
         self.assertEqual(self.t.matrix, [
-            dict(python="python2.6", env=dict(FOOBAR='0')),
+            dict(python="2.7", env=dict(FOOBAR='0'), os='linux',
+                 dist='precise', language='python'),
+        ])
+
+
+class TestBuildMatrix(TravisYmlTestCase):
+
+    def test_default_language(self):
+        matrix = self.t._build_matrix()
+
+        self.failUnlessEqual(matrix, [
+            dict(language='python', python="2.7"),
+        ])
+
+    def test_default_multiple_options(self):
+        self.t.config["python"] = ['2.7', '3.5']
+        matrix = self.t._build_matrix()
+
+        self.failUnlessEqual(matrix, [
+            dict(language='python', python="2.7"),
+            dict(language='python', python="3.5"),
+        ])
+
+    def test_language_with_dict(self):
+        self.t.default_matrix = {
+            'language': {
+                'c': {'compiler': 'gcc'}
+            }
+        }
+        self.t.language = "c"
+        self.t.config["language"] = "c"
+
+        matrix = self.t._build_matrix()
+
+        self.failUnlessEqual(matrix, [
+            dict(compiler='gcc', language='c'),
+        ])
+
+        # Now try again with multiple compilers to use.
+        self.t.config["compiler"] = ["gcc", "clang", "cc"]
+
+        matrix = self.t._build_matrix()
+
+        self.failUnlessEqual(matrix, [
+            dict(compiler='gcc', language='c'),
+            dict(compiler='clang', language='c'),
+            dict(compiler='cc', language='c'),
+        ])
+
+    def test_language_multiple_options(self):
+        self.t.default_matrix = {
+            'language': {
+                'ruby': {
+                    'gemfile': 'Gemfile',
+                    'jdk': 'openjdk7',
+                    'rvm': '2.2',
+                }
+            }
+        }
+        self.t.language = "ruby"
+        self.t.config["language"] = "ruby"
+
+        matrix = self.t._build_matrix()
+
+        self.failUnlessEqual(matrix, [
+            dict(gemfile='Gemfile', jdk='openjdk7', rvm='2.2', language='ruby'),
+        ])
+
+        # Start exploding the matrix
+        self.t.config["gemfile"] = ['Gemfile', 'gemfiles/a']
+
+        matrix = self.t._build_matrix()
+
+        self.failUnlessEqual(matrix, [
+            dict(gemfile='Gemfile', jdk='openjdk7', rvm='2.2', language='ruby'),
+            dict(gemfile='gemfiles/a', jdk='openjdk7', rvm='2.2', language='ruby'),
+        ])
+
+        self.t.config["rvm"] = ['2.2', 'jruby']
+
+        matrix = self.t._build_matrix()
+
+        self.failUnlessEqual(matrix, [
+            dict(gemfile='Gemfile', jdk='openjdk7', rvm='2.2', language='ruby'),
+            dict(gemfile='Gemfile', jdk='openjdk7', rvm='jruby', language='ruby'),
+            dict(gemfile='gemfiles/a', jdk='openjdk7', rvm='2.2', language='ruby'),
+            dict(gemfile='gemfiles/a', jdk='openjdk7', rvm='jruby', language='ruby'),
+        ])
+
+        self.t.config["jdk"] = ['openjdk7', 'oraclejdk7']
+
+        matrix = self.t._build_matrix()
+
+        self.failUnlessEqual(matrix, [
+            dict(gemfile='Gemfile', jdk='openjdk7', rvm='2.2', language='ruby'),
+            dict(gemfile='Gemfile', jdk='openjdk7', rvm='jruby', language='ruby'),
+            dict(gemfile='Gemfile', jdk='oraclejdk7', rvm='2.2', language='ruby'),
+            dict(gemfile='Gemfile', jdk='oraclejdk7', rvm='jruby', language='ruby'),
+            dict(gemfile='gemfiles/a', jdk='openjdk7', rvm='2.2', language='ruby'),
+            dict(gemfile='gemfiles/a', jdk='openjdk7', rvm='jruby', language='ruby'),
+            dict(gemfile='gemfiles/a', jdk='oraclejdk7', rvm='2.2', language='ruby'),
+            dict(gemfile='gemfiles/a', jdk='oraclejdk7', rvm='jruby', language='ruby'),
+        ])
+
+
+class TestOsMatrix(TravisYmlTestCase):
+
+    def test_os_matrix(self):
+        build_matrix = [dict(language='python', python='2.7')]
+
+        matrix = self.t._os_matrix(build_matrix)
+
+        self.failUnlessEqual(matrix, [
+            dict(os='linux', dist='precise', language='python', python='2.7')
+        ])
+
+    def test_multiple_dists(self):
+        build_matrix = [dict(language='python', python='2.7')]
+        self.t.config["dist"] = ["precise", "trusty", "xenial"]
+
+        matrix = self.t._os_matrix(build_matrix)
+
+        self.failUnlessEqual(matrix, [
+            dict(os='linux', dist='precise', language='python', python='2.7'),
+            dict(os='linux', dist='trusty', language='python', python='2.7'),
+            dict(os='linux', dist='xenial', language='python', python='2.7'),
         ])
 
 
@@ -145,66 +277,74 @@ class TestMatrix(TravisYmlTestCase):
     def test_exclude_match(self):
         self.t.config["env"] = ["FOO=1 BAR=2", "FOO=2 BAR=1"]
         m = self.t.config["matrix"] = {}
-        m['exclude'] = [dict(python="python2.6", env="FOO=2 BAR=1")]
+        m['exclude'] = [dict(python="2.7", env="FOO=2 BAR=1")]
 
         self.t.parse_envs()
         self.t.parse_matrix()
 
         self.assertEqual(self.t.matrix, [
-            dict(python="python2.6", env=dict(FOO='1', BAR='2')),
+            dict(python="2.7", env=dict(FOO='1', BAR='2'), os='linux',
+                 dist='precise', language='python'),
         ])
 
     def test_exclude_subset_match(self):
         self.t.config["env"] = ["FOO=1 BAR=2", "FOO=2 BAR=1 SPAM=3"]
         m = self.t.config["matrix"] = {}
-        m['exclude'] = [dict(python="python2.6", env="FOO=2 BAR=1")]
+        m['exclude'] = [dict(python="2.7", env="FOO=2 BAR=1")]
 
         self.t.parse_envs()
         self.t.parse_matrix()
 
         self.assertEqual(self.t.matrix, [
-            dict(python="python2.6", env=dict(FOO='1', BAR='2')),
+            dict(python="2.7", env=dict(FOO='1', BAR='2'), os='linux',
+                 dist='precise', language='python'),
         ])
 
     def test_exclude_nomatch(self):
         self.t.config["env"] = ["FOO=1 BAR=2", "FOO=2 BAR=1"]
         m = self.t.config["matrix"] = {}
-        m['exclude'] = [dict(python="python2.6", env="FOO=2 BAR=3")]
+        m['exclude'] = [dict(python="2.7", env="FOO=2 BAR=3")]
 
         self.t.parse_envs()
         self.t.parse_matrix()
 
         self.assertEqual(self.t.matrix, [
-            dict(python="python2.6", env=dict(FOO='1', BAR='2')),
-            dict(python="python2.6", env=dict(FOO='2', BAR='1')),
+            dict(python="2.7", env=dict(FOO='1', BAR='2'), os='linux',
+                 dist='precise', language='python'),
+            dict(python="2.7", env=dict(FOO='2', BAR='1'), os='linux',
+                 dist='precise', language='python'),
         ])
 
     def test_include(self):
         self.t.config["env"] = ["FOO=1 BAR=2", "FOO=2 BAR=1"]
         m = self.t.config["matrix"] = {}
-        m['include'] = [dict(python="python2.6", env="FOO=2 BAR=3")]
+        m['include'] = [dict(python="2.7", env="FOO=2 BAR=3")]
 
         self.t.parse_envs()
         self.t.parse_matrix()
 
         self.assertEqual(self.t.matrix, [
-            dict(python="python2.6", env=dict(FOO='1', BAR='2')),
-            dict(python="python2.6", env=dict(FOO='2', BAR='1')),
-            dict(python="python2.6", env=dict(FOO='2', BAR='3')),
+            dict(python="2.7", env=dict(FOO='1', BAR='2'), os='linux',
+                 dist='precise', language='python'),
+            dict(python="2.7", env=dict(FOO='2', BAR='1'), os='linux',
+                 dist='precise', language='python'),
+            dict(python="2.7", env=dict(FOO='2', BAR='3')),
         ])
 
     def test_include_with_global(self):
         self.t.config["env"] = {'global': "CI=true", 'matrix': ["FOO=1 BAR=2", "FOO=2 BAR=1"]}
         m = self.t.config["matrix"] = {}
-        m['include'] = [dict(python="python2.6", env="FOO=2 BAR=3")]
+        m['include'] = [dict(python="2.7", env="FOO=2 BAR=3")]
 
         self.t.parse_envs()
         self.t.parse_matrix()
 
         self.assertEqual(self.t.matrix, [
-            dict(python="python2.6", env=dict(FOO='1', BAR='2', CI='true')),
-            dict(python="python2.6", env=dict(FOO='2', BAR='1', CI='true')),
-            dict(python="python2.6", env=dict(FOO='2', BAR='3', CI='true')),
+            dict(python="2.7", env=dict(FOO='1', BAR='2', CI='true'),
+                 os='linux', dist='precise', language='python'),
+            dict(python="2.7", env=dict(FOO='2', BAR='1', CI='true'),
+                 os='linux', dist='precise', language='python'),
+            dict(python="2.7", env=dict(FOO='2', BAR='3', CI='true')),
         ])
 
 
diff --git a/buildbot_travis/travisyml.py b/buildbot_travis/travisyml.py
index 44ed673..25d7e02 100644
--- a/buildbot_travis/travisyml.py
+++ b/buildbot_travis/travisyml.py
@@ -17,7 +17,9 @@
 from __future__ import print_function
 from future.utils import string_types
 
+import itertools
 import re
+from copy import deepcopy
 
 import yaml
 from buildbot.plugins import util
@@ -26,6 +28,18 @@
 TRAVIS_HOOKS = ("before_install", "install", "after_install", "before_script",
                 "script", "after_script")
 
+DEFAULT_MATRIX = {
+    'os': (
+        'linux',
+    ),
+    'dist': (
+        'precise',
+    ),
+    'language': {
+        'python': ('2.7',),
+    },
+}
+
 
 class TravisYmlInvalid(Exception):
     pass
@@ -93,7 +107,7 @@ class TravisYml(object):
     Loads a .travis.yml file and parses it.
     """
 
-    def __init__(self):
+    def __init__(self, cfgdict=None):
         self.language = None
         self.image = None
         self.environments = [{}]
@@ -105,6 +119,10 @@ def __init__(self):
         self.email = TravisYmlEmail()
         self.irc = TravisYmlIrc()
         self.config = None
+        self.default_matrix = deepcopy(DEFAULT_MATRIX)
+        self.cfgdict = {}
+        if cfgdict:
+            self.cfgdict = cfgdict
 
     def parse(self, config_input):
         try:
@@ -115,6 +133,7 @@ def parse(self, config_input):
 
     def parse_dict(self, config):
         self.config = config
+        self.load_cfgdict_options()
         self.parse_language()
         self.parse_label_mapping()
         self.parse_envs()
@@ -124,6 +143,14 @@ def parse_dict(self, config):
         self.parse_notifications_email()
         self.parse_notifications_irc()
 
+    def load_cfgdict_options(self):
+        default_matrix = self.cfgdict.get('default_matrix')
+        if isinstance(default_matrix, dict):
+            self.default_matrix.update(default_matrix)
+            for k, v in self.default_matrix.iteritems():
+                if isinstance(v, basestring):
+                    self.default_matrix[k] = [v]
+
     def parse_language(self):
         try:
             self.language = self.config['language']
@@ -184,17 +211,69 @@ def parse_branches(self):
         raise TravisYmlInvalid(
             "'branches' parameter contains neither 'only' nor 'except'")
 
-    def parse_matrix(self):
+    def _build_matrix(self):
         matrix = []
-        python = self.config.get("python", ["python2.6"])
-        if not isinstance(python, list):
-            python = [python]
         # First of all, build the implicit matrix
-        for lang in python:
-            for env in self.environments:
-                matrix.append(dict(
-                    python=lang,
-                    env=env, ))
+        supported_languages = self.default_matrix.get('language', {})
+        language_options = supported_languages.get(self.language)
+        if not isinstance(language_options, (dict, tuple, list)):
+            language_options = [language_options]
+        # Many languages use their name as the key to check for versions to use.
+        if isinstance(language_options, (tuple, list)):
+            for language_version in self.config.get(self.language, language_options):
+                matrix.append({'language': self.language,
+                               self.language: language_version})
+        elif isinstance(language_options, dict):
+            # Get a view of the keys this language supports. Use those
+            # keys to check if they specified in the config, otherwise
+            # use the defaults. Do a cross-product across all of the
+            # keys to get all of the combinations. Finally, zip together
+            # the keys and the particular combination to convert to a
+            # dict to populate the matrix.
+            build_matrix_keys = sorted(list(language_options.keys()))
+            matrix_versions = [self.config.get(k, language_options[k])
+                               for k in build_matrix_keys]
+            # Ensure everything is at least a list of the versions for this
+            # language.
+            matrix_versions = [v if isinstance(v, (tuple, list)) else [v]
+                               for v in matrix_versions]
+            for matrix_combination in itertools.product(*matrix_versions):
+                lang_matrix = dict(itertools.izip(build_matrix_keys,
+                                                  matrix_combination))
+                lang_matrix['language'] = self.language
+                matrix.append(lang_matrix)
+
+        return matrix
+
+    def _os_matrix(self, build_matrix):
+        # The language-level matrix has been built. Merge that with the os and
+        # dist options from the config.
+        matrix = []
+        os_options = self.config.get('os', self.default_matrix['os'])
+        if isinstance(os_options, basestring):
+            os_options = [os_options]
+        dist_options = self.config.get('dist', self.default_matrix['dist'])
+        if isinstance(dist_options, basestring):
+            dist_options = [dist_options]
+        for os in os_options:
+            for dist in dist_options:
+                for build_config in build_matrix:
+                    os_matrix = build_config.copy()
+                    os_matrix['os'] = os
+                    os_matrix['dist'] = dist
+                    matrix.append(os_matrix)
+
+        return matrix
+
+    def parse_matrix(self):
+        build_matrix = self._build_matrix()
+        os_matrix = self._os_matrix(build_matrix)
+        matrix = []
+        for env in self.environments:
+            for mat in os_matrix:
+                mat = mat.copy()
+                mat['env'] = env
+                matrix.append(mat)
 
         cfg = self.config.get("matrix", {})